Petroleum mahogany sulphonic products



Patented Mar. 19, 1946 PETROLEUM MAHOGANY SULPHONIC PRODUCTS ManuelBlumer, Petrolia, Pa, asslgnor to L.

Sonneborn Sons, Inc., New York, N. 1., a corporation of Delaware NoDrawing. Application October 19, 1943,

Serial No. 508,896 7 13 Claims.

This invention relates to new and useful improvements in petroleummahogany sulphonic products.

In the acid refining of petroleum hydrocarbons under sulphonatingconditions, there are recovered in the oil layer after acid treatment,certain sulphonic acids generally referred to as mahogany petroleumsulphonic acids by reason of the color which they impart to the oillayer in which they occur. These mahogany petroleum sulphonic acidsoriginally constituted limitedly valued by-products, particularly ofwhite oil refining. However, these products have since become valuableas additives, detergents, emulsifying agents, etc.; in fact they are,valuable to such an extent today, that their production is often theprime purpose of petroleum hydrocarbon sulphonation treatments.

In accordance with hitherto known methods of procuring petroleummahogany sulphonic products, including both the free acids, as well astheir salts, only relatively poor yields were obtained and in allcommercially practicable operations the products obtained werecontaminated by colored or color-inducing substances, primarilyresulting from the presence of polymers, tarry and the like products.

Attempts to increase the of appreciable after-treatment or refining andto obtain in many cases yields of a magnitude hitherto not commerciallyobtainable.

The process in accordance with my invention essentially and broadlycomprises the thorough mixing of an acidified oil and preferably anonsettled oil as it results from the acid treatment of a petroleumhydrocarbon stock under conventional' sulphonating conditionswith asuitable organic solvent to thereby obtain a top layer essentiallycomprising mahogany sulphonic acids, solvent and oil and thereafterrecovering mahogany sulphonic acids or their salts preferably in oilsolution from the solvent layer. 7

Within the preferred embodiment of my in vention and to obtain maximumyields, I find it of advantage to modify the conventional acid treatmentof a petroleum hydrocarbon oil stock to be used in the procedure inaccordance with my invention. Accordingly, I pretreat a petroleumhydrocarbon stock with relatively small amounts and preferably notappreciably in excess of by weight of fuming or concentrated sulphuricacid and preferably with a concentrated sulphuric 1 acid of about 66 B.at sulphonating tempera- 1 ture for the oil which is best selectedbetween 125518, and 175 F. and preferably at 150 F. and

yield of mahogany sulphonic products by increasing the amount ofconcentration of acid to thereby obtain a boosted sulphonation reactionare usually accompanied by a deterioration of the color due to theincreased formation of these objectionable sulphonation by-productsresponsible for the dark color of the resultant products. By reason ofthe fact that many of the uses to which petroleum mahogany sulphonicproducts are put, such as for instance in textile treating thereafterfollow this acid pretreatment by the addition of S03 preferablyintroduced by way of fuming sulphuric acid and preferably oleum of oilsand various emulsification uses, it is necessary that the products be aslight in color as possible so as not to impart an objectionable tint orcoloration to the materials with which they come into contact in thecourse of a particular treatment. As a result of the necessity forsubstantial freedom from objectionable discoloration of petroleummahogany sulphonic products, it has therefore been necessary in the pastto resort to cumbersome, uneconomical, costly and time consumingoperations and devices, to bring these productsto the state of desiredrefinement, i. e. relatively low color value. i 7

I I have discovered a new method in accordance with which it is possibleto obtain petroleum sulphonic acid products-substantially free fromallobjectionable discoloration or discoloring matters about 20% S03 contentat a temperature of between F. and 160 F. and preferably between F. and1409f". Addition of S03 as such as well as addition of SO: by way offuming sulphuric acid having an S03 content appreciably in excess of 20%produces more heavily viscous sludges presenting well known operationaldimculties. For best results it is advisable to permit settling of acidsludge after'the pretreatment preferably at a temperature of between andF. and to remove the sludge layer prior to the subsequent S0: or fumingsulphuric acid treatment.

The resulting reaction mix containing both acidified oil as well as acidsludge is then thor-j oughly mixed with the solvent as for instance Vbenzol, preferably in a volume ratio of solvent to and for best resultsof total reaction mix of 0.3 T to uln Whereas approximately the volumeratio gives normally the highest yields,

asfor instance a volume ratio of 7 does not ordinarily produce yieldsmateriall higher than obtained by the use of the volume ratio.

The solvent treatment as such, does not normally require criticaltemperature conditions. It is preferred however to so adjust thetemperature that the mix after agitation may be left to settle andstratify at a temperature between 125 F. and 140 F. In the practicaloperation of my invention therefore, it is normally advisable to add thesolvent to the acidified mix immediately after the oleum treatment andwhile the same is still at about the sulphonation employed. In suchcase, if the addition of the solvent results in a material lowering ofthe temperature, it may be of advantage to raise the temperature of themix to between 125 F. and 140 F. for best stratification results.

The resulting toplayer of the mix essentially contains unreacted oil,petroleum mahogany sulphonic acids and solvent, whereas the bottom layeris essentially an acid sludge layer containing unreacted acid, tarrymaterials and petroleum green sulphonic acids, which latter areessentially water-soluble and oil-insoluble. The petroleum mahoganysulphonic acids may then be recovered as such but preferably in the formof the alkali salts from the solvent layer. It is preferred, however, toneutralize the acidity of the solvent layer by a suitable caustic, asfor instance a 25 Be. sodium caustic soda solution and preferably to thephenolphthaleine end point, whereupon stratification occurs, leaving anupper substantially neutral solvent layer and an aqueous layer of spentcaustic solution. The latter layer is withdrawn and the solvent layer ispreferably first washed for removal of salts and then worked up byremoving the solvent, such as by distillation, to leave mahoganysulphonates in solution in oil. If for any reason it should be desiredto recover the sulphonates from this oil solution, this may be done. Insolvent cases, the oil solution is dehydrated to remove final traces ofwater and then used as such, asin the macolorless, and measured in colorvalues possess less than 13 and usually between. 0.25 and 051?.(Lovibond cell).

Within the scope of my invention the petroleum hydrocarbon oil that-Iprefer to use'as a starting material is a straight overhead distillatepreferably from a Texas or Gulf Coast crude and specifically anon-solvent refined stock having a Saybolt viscosity of 150 seconds orhigher at 100 F. L

Satisfactory solvents in accordance with this invention are benzol andits normally liquid homologues, normally liquid chlorinated benzol orbenzol homologues and normally liquid saturated chlorinated aliphatichydrocarbons. Specific solvents of this type and nature are for instancebenzol, chlorbenzol, carbon tetrachloride and ethylene dichloride. Inthe majority of cases benzol constitutes the preferre solvent.

When proceeding within the preferred embodiment of my invention I preferto use from 60 to 100% total acids, i. e. both concentrated sulphuricacid and oleum by weight calculated on the total weight of thehydrocarbon stock to be sulphonated. For best results I find it ofadvantage to use for the pretreatment from 15 to 50% and preferably 15%concentrated sui- I Example I 1000 parts by weight of a Gulf Texas 500"viscosity (Saybolt at 100 F.) oil is treated with jority of cases it isdesirable to use oil as a carrier parts by weight of. 66 B. sulphuricacid at F. The acid is relatively slowly stirred in with thoroughagitation. After addition of the acid the mix is permitted to stratifyand the acid sludge formed settles. During stratification thetemperature is maintained at 150 F. Upon completed stratification theacid sludge is withdrawn. Thereafter 500 parts by weight of oleum areagitated into the oil at 150 F. followed by the addition of benzol involume substantially equal to the volume of acidified mix. The entiremix is permitted to stratify and the bottom layer of acid sludge iswithdrawn and the upper benzol acidified oil laveris neutralized with 27B. caustic soda to phenolphthaleine end point. The neutralized mix isallowed to settle and the spent caustic layer is withdrawn. The upperlayer is then transferred to a still and the benzol distilled off. Themahogany sulphonate in' oil solution is then dehydrated and withdrawn.

Example II 1000 parts by weight of a Gulf Texas 750" viscosity (Sayboltat 100 F.)' oil is treated with 100 parts by weight of 66 B. sulphuricacid at about 150 F. with vigorous stirring, whereupon after addition ofthe acid the sludge formed is permitted to settle while maintaining thetem' perature at 150 F. The sludge is thereafter removed and theremaining oil layer is treated with 15% by weight of pure anhydrous sEat 150 F. -'I'he S0: is added preferably. ;diluted with air to aconcentration of about Tto' 10%of $02. The air S0: mixture is inducedinto the oil by means of any conventional gas dispersing means.

After completion of the addition of the $0: a volume of benzol equal tothe volume of total After the addition of settled a pletely stableemulsi Y limited by acidified mix is added with vigorous s the benzol iscompleted, to stratify and worked up recovery of mahogany petroleumsulas described in connection with Exthe mix-is permitted for thephonate ample I.

In lieu of the benzol specified in .the above Examples I and 11 anyother of the solvents useful in accordance with the invention; such ascarbon tetrachloride, diethylene dichloride. chlorbenzol or the like maybe used, all other treating conditions and steps remaining the same.

Within the broad purview of my invention an acidified oil layer as, forinstance, conventional obtained in sulphuric acid refining, may be used.This acidified oil layer may be subjected to the solvent treatment inaccordance with the inven tion, with or without prior removal of acidsludge. It is, however, preferred to take a noncid treated oil, i. e. anoil containing comparatively large amounts of acid sludge, thereindispersed. In many instances I find it advisable when using an acidtreated oil that has settled, to again disperse therein by suitableagitation the acid sludge stratified therefrom.

When resorting to the pretreatment in accordance with the preferredembodiment of my invention, I find it of advantage as hereinaboverelated, to remove for best results the acid sludge formed after thepretreatment. This removal state, however, though permitting theobtaining of superior results is not crltical'to the principle of theinvention and if desired may be omitted should such omission bedesirable for operational or other reasons.

The products obtained in accordance with the invention as above pointedout are substantially free from objectionable discoloring matters, i. e.polymers, tarry and sludge materials, and substantially possessed ofLovibond colors of values less than IR and usually between 0.25 and0.51% 1/2' Lovibond cell, they are spontaneously emulsifiable in waterand form substantially comons, especially upon the addition of minoramounts such as l to 2% of water and a suitable linking agent such asdiethylene glycol in similar concentration. g

The hydrocarbon oil solutions of the petroleum mahogany sulphonatesobtained in accordance with the invention normally contain from 70 v to80% and usually 75% of hydrocarbon oil and are substantially free fromsalts and other inorganic matter.

The foregoing description is furnished by way of illustration and not oflimitation, and it is,

therefore, my intention that the invention be the appended claims onlyor their wherein I have attempted to claim inherent novelty.

equivalents broadly all I claim: 1. Method for the production ofpetroleum mahogany sulphonic products which comprises treatv ing'anon-settled acidified petroleum hydrocarbon oil containing petroleummahogany sulphonic acids, acid sludge and unreacted oil, derived fromthe sulphuric acid treatment of a straight overhead distillate, having aSalbolt viscosity at 100 F. of at least 150 seconds, under sulphonatingconditions of acid amount and temperature, with an organic normallyliquidsolvent selected from the group consisting of normally liquidbenzol, benzol homologues, chlorbenzol, chlorinated benzol homologuesand saturated chlorinated aliphatic hydrocarbons, permitting thereaction mix to leum hydrocarbon oil sol hogany sulphonic acid layerpredominantly ogany sulphonic acids settle to thereby obtain a topcontaining petroleum mah and oil in solution in said solvent, andthereafter recovering from said layer a petroleum sulphonic product ofhigh purity substantially free from discoloring materials.

2. Method in accordance with claim 1 in which said solvent is benzohandin which said acidified oil is substantially non-settled.

3. Method in accordance with claim 1' in which said solvent is presentin vent to acidified oil from 0.3 1 v T r volume ratio of solin whichsaid top layeris neutralized and permitted to settle, to thereby form asecond top layer predominantly containing petroleum mahogany sulphonateand oil in solution in said solvent, and in which said second top layeris thereafter treated to recover therefrom a petroution of petroleummahogany sulphonates of high purity and substantially free fromdiscoloring materials.

4. Method for the production of petroleum mahogany sulphonic productswhich comprises treating a petroleum hydrocarbon stock of the straightoverhead distillate type, having a Saybolt viscosity at F. of at leastseconds, with concentrated sulphuric acid under sulphonating conditionsof acid amount and temperature, thereafter treat-= ing'the resultingstock with $03 under sulphonating conditions of acid amount'andtemperature, thereafter agitating the lastly resulting mix containingpetroleum mahogany siilphonic acids, acid sludge and unreacted normallyliquid solvent selected from the group consisting of normally liquidbenzol, benzol homologues, chlorbenzol, chlorinated benzol homologuesand saturated chlorinated aliphatic hydrocarbons, permitting the solventtreated mix to settle to thereby obtain a top layer predominantlycontaining a solventsolution of petroleum mabon stock andthereafter'recovering from said layer a. petroleum mahogany sulphonatepetroleum hydrocarbon solution of high purity and substantially freefrom discoloring materials.

5. Method for the production of petroleum mahogany sulphonic productswhich comprises treating a petroleum hydrocarbon stock of the straightoverhead distillate type, having a Saybolt viscosity at 100 F. of atleast 150 seconds, with a relatively small amount of concentratedsulphuric acid at a temperature between 125 and 175 F. to thereby formacid sludge, removing said acid sludge, treating the resulting stock ata temperature between 80 and. F. with fuming sulphuric acid to therebyform further amounts of acid sludge, agitating the resulting mixcontaining petroleum mahogany sulphonic acids, acid sludge and unreactedoil including acid sludge with an organic normally liquid solventselected from the group consisting of norm zol, benzol homologues,chlorbenzol, chlorinated benzol homologues and saturated chlorinatedaliphatic hydrocarbons, permitting v the solvent treated mixto settle tothereby attain a top layer predominantly containing a solvent solutionof petroleum mahogany sulphonic acid and petroleum hydrocarbon stock andthereafter recovering from said layer a petroleum mahogany sulphonatepetroleum hydrocarbon solution of high purity and substantially freefrom discoloring materials.

oil with an organic and petroleum hydrocar ally liquid ben-v 6. Methodin accordance with claim 5 in which said solvent is bcnzol.

'7. Method in accordance with claim 5 in which said solvent is presentin volume ratio or" solventto acidified oil from aseaers straightoverhead distillate type. having a Say- 7 bolt viscosity at 100 F. of atleast 150 seconds with from 15 to by weight of concentrated sulphonicacid at a temperature between 125 and 175 F. to thereby iorm acidsludge, removing said acid sludge, treating the resulting stock withfrom to 50% of fuming sulphuric acid by weight of hydrocarbon stockpresent, at a temperature between 80 and 160 F., the total sulphuricacid including concentrated and turning sulphuric acid being from 60 toby weight of said hydrocarbon stock. agitatingthe fuming sulphuric acidtreated mix containing acid sludge with an organic normally liquidsolvent selected from the group consisting of: normally liquid benzol,benzol homologues, chlorbenzol, chlorinated benzol homologues andsaturated chlorinated aliphatic hydrocarbons in volume ratio of solventto acidified stock from 0.3 l a 'i' .1

settling the solvent treated mix to thereby obtain a layer predominantlycontaining a solvent solution of petroleum mahogany sulphonic acid,neutralizing said layer to thereby form a top layer predominantlycontaining petroleum mahogany sulphonate and hydrocarbon oil in solutioninsaid solvent and thereafter treating said top layer to recovertherefrom a petroleum hydrocarbon ml solution of etroleum mahoganysulphonates of high purity and substantially free irom discoloringmaterials.

9. Method in accordance with claim 8 in which said solvent is benzolpresent in volume ratio of solvent to acidified stock from i if 1 10.Method in accordance with claim 8 in which said first formed acid sludgeis permitted to settle prior to. its removal at a temperature betweenand 160 F. and in which the solvent treated mix is left to settle andstratify at a temperature between 125 and F.

11. Method for the production of petroleum mahogany sulphonic productswhich comprises treating petroleum hydrocarbon stock 0! the straightoverhead distillate type. having a Saybolt viscosity at 100 F. of atleast seconds, with from 15 to 20% of 66 B. sulphuric acid by weight ofhydrocarbon stock at a temperature between 125 and 175 F. to therebyform acid sludge, permitting said acid sludge to settle at a temperaturebetween 140 and F., removing said acid sludge, treating the resultinghydrocarbon stock with from 80 to 85% o! oleum by weight of hydrocarbonstock at a temperature between 125 and 140 F. to thereby obtain i'urthersludge formation agitating the resulting mix including sludge containedtherein with benzoi in I a volume ratio 01 benzol to total mix oipermitting the benzol treated mix to settle at a temperature between 125and 140 F. to thereby obtain a first-top layer predominantly containinga benzol solution of petroleum mahogany sulphonic acid and I petroleumhydrocarbon stock, neutralizing said top layer permitting theneutralized top layer to settle to thereby form a second top layerpredominantly containing petroleum mahogany sulphonate and petroleumhydrocarbon oil in benzol solution and treating said second top layer torecover therefrom a petroleum hydrocarbon oil solution of petroleum ma-

